Issue
This article contains frequently asked questioned about Apache Kafka on Heroku Maintenance.
Resolution
Why is this maintenance happening?
Apache Kafka on Heroku is a managed Kafka offering, and one of the largest values provided is providing patches for security and feature updates. Heroku monitors for and proactively patches security vulnerabilities as part of its Apache Kafka on Heroku offering.
How can I protect my app against downtime and errors during maintenance?
Please follow our Robust Usage guidelines. This will not only protect you against errors during maintenance, but also during rare but possible Kafka node outages.
How long will maintenance take?
Maintenance duration depends on the cluster size and load. During maintenances, Kafka nodes are added before removing the old node. While this reduces cluster impact, this takes some time. Typically maintenances last a few days. For larger clusters, they may last up to a week.
During Kafka maintenance, Kafka clients may see small amounts of errors as partitions move between brokers.
How do I find the maintenance status?
Use the heroku kafka:info command to check whether your kafka cluster's status. A status of undergoing maintenance last for the duration of the maintenance.
=== KAFKA_URL
Plan: heroku-kafka:standard-0
Status: undergoing maintenance
...
How do I resolve NotLeaderForPartitionException errors?
The fastest and most simple way to recover from this error is to restart your consumer and producer dynos.
For more information on preventing this error, please refer to the Partition Leader section of our Robust Usage document.
Why did the maintenance happen outside of the maintenance window?
Heroku doesn't schedule maintenance events for Apache Kafka on Heroku during an app's maintenance window. We send a notice when the maintenance starts and ends. Maintenance events for Apache Kafka on Heroku happen every 90 days or four times a year.